Alloy steel



Patented Feb. 17, 1925.

. um'rso 'srA'rss PATENT OFFICE."

ARTHUR e. .nnvmson, or BnonxvILLE, NEW YORK, ASSIGNQR T 1). 00., me, orI :anw yonx, N. 2., a conronnrron on NEW YORK.

1W0 Drawing.

- To all whom it may cmwem:

Be it known that I, ARTHUR C. DAVIDSON, a citizen of the United States,and a resident of Bronxville,-in the county of West- 6 chester and Stateof New York,-liave invented. .certain new and useful Im rovements inAlloy Steel, of which the ollowing is a specification. I his inventionrelates to alloysteel and 10 has for its object to -provide a steelwhich i can be cast directly fromthe melt into tools such as forturning, milling cutters, countersinks, rea ers, dies, bar stock, etc.,of

only' slight y greater section than the' finished article, and onlyrequiring to be finished-by fgrinding and heat treatment, without theorging, rolli and machining operations now customari y employed in' 1finishing into tools steel-from ingots. Be-

?2 sides a saving in 'labor of up to-90%, this invention provides asteel which outlasts the best brandsof forged steel'now on the market byfrom two to upwards of ten times,

' requires less frequent grinding, and will work at higher cuttingspeeds than are at present considered practicable.

Such a steel must be homogeneous, of

character to properly fill in the mold, and

capable of being castlwith a minimum loss in usable castings from headsand risers.

.A' crucible .steel'cast at 34100915. and-upwards and varying .inanalysis between the percentage lim ts given below, according to theduty to be erformed, has given extremely successfu results in practice:tang: sten, 14.00-22.00; vanadium, .50-3.00; c'hromium, 2.00-12.00;zirconium, ..50-6.00; cobalt, LOO-8.00; carbon, .35-125, the balancebeing ironi and impurities,-in which 40 latter class I inc ude siliconand man anese, which may varf from .02 to 1.30, an .05 to 1.00,respective without material efiect on the results. nutetraces ofphosphorus and sulphur mayalso be found in the analysis depending on thepurit of materials 'usedior the base,'the materia of the crucible,:etc.Vanadium or cobalt, or both, may

be omitted insome instances without dot-- riment to---the steel, forspecial purposes, but bcgtfiing tools are improved by includ- 1ng't. Ananalysis suitable a? lathe tools, tool heated to 2200, F.

for use after'grmdingand heat Application filed October 28, 1919. SerialNo. 333,967.

holder bits, etc., in percentages, is tungsten, 18.00; vanad1um,1.50;'chromium, 7.00; z'irconium, 1.00; cobalt, 5.00; carbon, .65.

The iron should generally be 60%. With the higher percentages oftungsten}, etc.,

this steel will readily forge with ordinary methods and special care,but at the lower range of heat it is only forgeable with difficulty andcare, but this does not improve the cutting qualities materially.Forging ordinarily will injure them, owing to setting up of strains,cracks, etc., which annealing will not remove, but which will developafter quenching, or in use.

The steel is cast at from 3200 F. up-

ward, and sharply fills out the mold with- -When taken out of the mold,the castings may be cleaned and annealed, then (mud. or upwa thenquenched, preferably in oil, and drawn at about 800 F., or as theexperience of the hardener after a few tests will indicate. No checks orcracks develop during'thistreatment, which often occur with forged steeland castings even when treated at a lower temperature. The tool is thenground to size ready for use. Sand molds may be used, rammed hard eitherin a machine or by hand, and give-very sharp and accurate castings. r

I claim: p

.1. Alloysteelcomprising zirconium in combination with iron, tungsten,chromium and vanadium between the limits of the proportions specified.

2. Alloy steel comprising zirconium in combination with iron, tungsten,chromium,

cobalt and vanadium between the limits of the proportions specified.

3. "A cast alloy steel cutting 1 ready eatment without rolling, forgingor machine cutting work comprising iron, tungsten, chromium, cobalt andzirconium between the limits of theproportions specified.

4. A cast alloy steel cutting tuck tech for use-after grmding and hemfian'cctment withcut rolling, forging or Tm.- cutting work comprisingimn, tungsten, chm, cobalt, vanadmm and zu'comum between the limits ofthe proportions specified.

5. Alloy steel comprising gsten 18%,

v mizcmg vanadium 1.5%, chromium 7%, zirconium 7 1%, cobalt 5%, andcarbon .65%, in combinaticfn with iron.

Siedi at the city 0f New York, in the county cud State of New York, this24th day of October A, D, 1919;

